This study evaluated the relative effectiveness of two concurrent training regimens, differing only in the duration of the rest between the strength and endurance training sessions, on increases in strength. Physically active untrained males (N = 24) completed six weeks of training in one of three groups: same day concurrent training, alternate day concurrent training, or strength training only. Three training sessions were conducted per week. Body composition measures, VO2max, 1 RM bench press, and 1 RM hack-squat were measured before and after training.

Significant improvements over the time of the study occurred in the 1 RM bench press, 1 RM hack-squat, VO2max, and free-fat mass while percent body fat decreased. There were no significant differences between groups in any data.

Implication. Training for strength and endurance concurrently does not cause any adaptive interference between the two modes of activity.